1. Field
The following description relates to a Brushless Direct Current (BLDC) motor using Direct Current (DC) power and Alternating Current (AC) power, and a corded or a cordless cleaner including the same.
2. Description of the Related Art
A motor is a machine configured to obtain torque from electrical energy, and is provided with a stator and a rotor. The rotor and the stator are configured to have an electromagnetic interaction with each other so that the motor is rotated by a force between a magnetic field and an electric current flowing through a coil.
A universal motor is mainly used as a driving motor for a conventional cleaner. The universal motor has an advantage of low cost because expensive components are not used and a controller is not needed. However, the universal motor needs a commutator and a brush, thereby reducing the efficiency of the motor and having a limited lifespan. In addition, although a hybrid motor that can operate on both DC and AC power, it is difficult for the universal motor to have the same suction force when DC power is applied and when AC power is applied due to lack of a space for inside coils.
Therefore, research on a cleaner Brushless Direct Current (BLDC) motor having high energy density and improved structural strength has been actively conducted.
Generally, the BLDC motor uses an inverter circuit that consists of a switching element instead of a brush and a commutator. Therefore, there is no need of replacing the brush, and there is small amount of electromagnetic interchange and noise.
The BLDC motor is widely applied to products, such as, a cleaner, a refrigerator, an air conditioner compressor, a washing machine, and the like, which require a high efficiency and variable speed.
In addition, to realize the same suction force when DC power is applied and when AC power is applied, the BLDC motor that can operate on both DC and AC power may use a DC motor and an AC motor. Alternatively, by using a boost circuit, DC voltage is increased to the same level of AC voltage or if using a buck circuit, AC voltage is decreased to the same level of DC voltage.